Relay for distant control



. Oct. 18, 1932. NA 1,883,783

RELAY FOR DISTANT CONTROL Filed Feb. 17, 1932 2 Sheets-Sheet 1 figj 9 :4 n7 T z F- 5 l8 l6 I9 TJ W 4 i E. GRANAT RELAY FOR DISTANT CONTROL Oct, 18, 1932.

2 Sheets-Sheet 2 Filed Feb. 17, 1932 Patented Oct. 18, 1932 UNITED STATES PATENT OFFICE ELIE GRANAT, OF PARIS, FRANCE, ASSIGNOR OF ONE-HALF T0 COMPAGNIE DES FORGES ET ACIERIES DE LA. MARINE ET DI-IOMECOURT, OF PARIS, FRANCE, A COMPANY OF FRANCE RELAY FOR .IDISTAN'I. CONTROL Application filed February 17, 1932, Serial No. 593,671, and in France June 26, 1928.

My invention is a divisional continuation in part of that disclosed in my prior application Ser. No. 343,352.

My invention has for its object a distant control device afiording means for a large power magnification of the type comprising a generator driven at a constant speed acting as the main transmitter and feeding the receivers with a current the frequency of which is variable, said generator being fed with an exciting current the frequency of which may be varied at will from its normal zero value.

Such distant control devices have been used heretofore with a transmitter constituted by a single generator which obviously cannot provide the considerable power magnification required say for controlling at a distance through a gyroscopic compass, a log, a distant order transmitting apparatus or the like device providing a very small torque, a part requiring a very large torque such as a ships rudder.

Now the power in the excitation of an electric machine is a fraction of the total power of the machine which may reach in certain cases, the exceptionally low figure of 1/100; but in the case of a distant control with a rotary inducing field this figure is much greater owing to the interaction between the rotary field and the inducing field itself.

Consequently the use of an amplifier constituted by a single machine is considerably restricted as to its field of application when the ratio of magnification is very large.

I have theretofore been led to find means for increasing the ratio of magnification afforded by such control devices having a limited ratio of magnification. This has brought me to conceive a series arrangement of several elementary amplifying machines. Such an arrangement had never been proposed heretofore and it is necessary to solve for allowing said series arrangement certain problems due to the following difliculties.

In the case of the application of this series arrangement to a distant control device of the above disclosed type, the mere arrangement in series of the generators does not provide the desired result because the voltage of the last machine tends towards zero. This is due to the fact that the inducing current of the generator and consequently the voltage at the terminals of the machine varies in proportion with the speed of rotation 01) of the field. Consequently, even in the case of a compensating winding existing, the voltage available at the terminals of the excitation winding of the second generator is not constant and depends on Similarly the voltage at the terminals of the second generator varies with the fraction The mere application of several machines in series does not therefore yield the desired result.

For this reason and with a view to remove these drawbacks, I use adjusting means constituted by resistances the use of which produces a new and interesting result as disclosed hereinafter.

I have described hereinbelow merely by way of example and shown on appended drawings a form of execution of my invention.

Fig. 1 is a diagram of the distant control device of the type described fed with direct or one-phase current and comprising the usual single generator.

Fig. 2 shows a distant control device of the same type comprising several generators in series according to my invention.

The device shown on Fig. 1 comprises a main transmitter T with its stator 1 and rotor 2. The stator 1 is provided with a distributed winding and is fed through the wires 10 and the resistances 10. The rotor Qhas a distributed winding connected with a commutator 3 on which rub N stationary brushes three in the case illustrated; these brushes 4.-56 are connected with the wires 7.

The rotor is driven by any suitable means such as an electric, thermic or hydraulic motor M.

The inducing stator of the transmitter T is fed through an auxiliary control transmitter T This transmitter may be either static or dynamic.

I have shown by way of example on Fig. 1 an auxiliary dynamic transmitter comprising a stator 11 of the distributed winding or of the salient pole type fed from the mains and a rotor 12 provided with a distributed winding connected with a commutator 13 on which rub two stationary feeding brushes connected with the mains and three movable brushes 1415--16 controlled by the control device 35 shown as a handwheel.

These movable brushes are connected with the three rings 17] 8-19 on which rub the three brushes 202122 connected with the wires 10 feeding the stator of the main transmitter.

The brushes 4-56 of the main transmitter are connected through the wires 7 with a certain number of receivers B Each receiver comprises a rotor 23 provided with a distributed winding connected with N rings through N equidistant points of the winding (N being equal to three in the case of the figure).

These three rings 24-25-26 are connected through the brushes 27, 28 and 29 with the brushes 4 56 of the main transmitter T The stator 30 of each receiver has salient I poles or a distributed winding fed from the mains through the wires 71.

. The stator 1 of the transmitter T may be provided moreover with a compensating Winding of any suitable type.

The working of the arrangement is as follows:

When the control device 35 is stationary the potentials at the brushes 14L1516 of the auxiliary transmitter remain constant, whereby a stationary inducing field is caused to arise in the main transmitter.

The result is that the potentials at the brushes 4-56 are constant whereby the rotor field in the several receivers R remains stationary. I

The inducing field in the stator 30 being also stationary, the rotor 23 remains stationary with the two fields in substantial coincidence.

Now if the brushes 141516 are moved, the direction of the inducing field of the transmitter T will be moved through an equal or a proportional amount.

To this new position given to the inducing field of the transmitter T corresponds a new distribution of the potentials at the brushes 456 and consequently the rotor field in the receivers such as R and R will be shifted by a corresponding amount; as these fields have a tendency to remain in eo- It should be noted that due to the multiple adjusting means provided, any characteristic curve may be obtained (said curve being that giving the relation between the torque and the speed and starting position of the controlled part). fact that the importance of the amplification can be modified by acting on the two following variables.

(a)The voltage of the exciting coil of the main transmitter T which may be controlled either through the insertion of a resistance 10 in the wires 10 or through a modification of the feed voltage from transmitter T (b)-The speed of rotation of the motor M.

The above disclosed adjustments will have as a consequence a modification in the energy transmi ted through the wires 7 to the rotor 23 of each receiverR and R Moreover the characteristic curve giving the relation between the torque and the speed of each receiver may be modifiedseparately according to requirements by acting on the excitation of the receiver considered.

It is thus possible to obtain at the receivers by using these adjusting means together, any desired law between the torque and the speed, this law depending both on the starting position of the controlled part and on the control speed required.

This method for transmission may be generalized as follows according to my invention as shown on Figure 2 showing a distant control with several transmitters in series.

The first main transmitter T feeds through its brushes 45-6 the excitation coils of a more powerful transmitter T driven by the same motor M. This transmitter T may feed in its turn the excitation of a transmitter T driven by the same shaft and so on.

I may thus provide a considerable energy at the output of the last transmitter, the currents acted upon at the auxiliary transmitter T remaining however very small.

I have provided moreover automatic means comprising a regulator controlled say by the auxiliary motor driving the brushes, for the automatic adjustment of the excitation volt age of the main transmitter, of the speed of rotation of the driving motor M or of any other desired variable.

This is provided by the ,/R Pw E1 (1%) If it is desired to keep the voltage E constant it is necessary to constrain R to vary with w according to a predetermined law such that the total impedance is constant; this can be provided for instance by a centrifugal regulator C mounted on the shaft of the control device (replaced preferably by an auxiliary motor controlled by the rotation of said shaft) and acting mechanically on the three phase rheostat 10 inserted between T and T in a manner such that:

R +Z w =K K being a constant. The resistance R of the exciting circuit of T should be controlled similarly in a manner such that R +Z w =K K being a coni must vary with w according to a predetermined law different from the preceding which is possible through a suitable calibration of the rheostat.

In fact any predetermined law of variation of the torque may be provided in the same manner, for instance that required for the driving of propellers which as is known require a maximum torque for a certain speed of rotation.

Of course the regulator instead of acting on the resistance of the successive exciting circuits or of the feed circuit of the auxiliary transmitter, may act in any suitable manner on the speed of rotation of the driving motor M or in fact both adjustments may be combined.

It may be of advantage to feed the auxiliary transmitter T from constant intensity mains and to provide a self adjustment of 'the intensity flowing out of a given generator, say T by making said intensity act on the speed of the motor M in order to return it to its normal value.

In my copending application Ser. No. 57 6,- 865 I have described a control device of a similar type but I do not wish to claim herein anything that is claimed in said copending application.

What I claim is:

1. A polyphase distant control device comprising a series of generators each constituted by two windings, common adjustable means for making one winding of each generator rotate with reference to the other with the desired angular velocity, an auxiliary transmitter feeding one winding of the first generator, means whereby the excited winding of each generator feeds the exciting winding of the next generator, receivers each constituted by two windings adapted to rotate one with reference to the other, wires connecting one winding of each receiver with the excited winding of the last generator, a rotary part at the auxiliary transmitter adapted to modify the frequency of the current fed to the first generator, means for controlling the generator exciting current and making its intensity follow a predetermined law and means for feeding the second windings of the receivers with current adapted to restore the angular concordance between the fields of the receivers when the rotary part is stationary.

2. In a device as claimed in claim 1 the provision of automatic means whereby the current adjusting means is caused to de pen d on the movement of the rotary part.

3. In a device as claimed in claim 1 the provision of automatic means whereby the current adjusting means is caused to depend on the speed of the means making the generator windings rotate.

4. In a device as claimed in claim 1 the provision of automatic means whereby the means making the generator windings rotate are controlled as to their speed by the current adjusting means and means whereby the latter is caused to depend on the movement of the rotary part.

In testimony whereof I have aflixed my signature ELIE GRANA'I. 

